linux/fs/nfsd/nfsxdr.c
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   1/*
   2 * XDR support for nfsd
   3 *
   4 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   5 */
   6
   7#include "vfs.h"
   8#include "xdr.h"
   9#include "auth.h"
  10
  11#define NFSDDBG_FACILITY                NFSDDBG_XDR
  12
  13/*
  14 * Mapping of S_IF* types to NFS file types
  15 */
  16static u32      nfs_ftypes[] = {
  17        NFNON,  NFCHR,  NFCHR, NFBAD,
  18        NFDIR,  NFBAD,  NFBLK, NFBAD,
  19        NFREG,  NFBAD,  NFLNK, NFBAD,
  20        NFSOCK, NFBAD,  NFLNK, NFBAD,
  21};
  22
  23
  24/*
  25 * XDR functions for basic NFS types
  26 */
  27static __be32 *
  28decode_fh(__be32 *p, struct svc_fh *fhp)
  29{
  30        fh_init(fhp, NFS_FHSIZE);
  31        memcpy(&fhp->fh_handle.fh_base, p, NFS_FHSIZE);
  32        fhp->fh_handle.fh_size = NFS_FHSIZE;
  33
  34        /* FIXME: Look up export pointer here and verify
  35         * Sun Secure RPC if requested */
  36        return p + (NFS_FHSIZE >> 2);
  37}
  38
  39/* Helper function for NFSv2 ACL code */
  40__be32 *nfs2svc_decode_fh(__be32 *p, struct svc_fh *fhp)
  41{
  42        return decode_fh(p, fhp);
  43}
  44
  45static __be32 *
  46encode_fh(__be32 *p, struct svc_fh *fhp)
  47{
  48        memcpy(p, &fhp->fh_handle.fh_base, NFS_FHSIZE);
  49        return p + (NFS_FHSIZE>> 2);
  50}
  51
  52/*
  53 * Decode a file name and make sure that the path contains
  54 * no slashes or null bytes.
  55 */
  56static __be32 *
  57decode_filename(__be32 *p, char **namp, unsigned int *lenp)
  58{
  59        char            *name;
  60        unsigned int    i;
  61
  62        if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXNAMLEN)) != NULL) {
  63                for (i = 0, name = *namp; i < *lenp; i++, name++) {
  64                        if (*name == '\0' || *name == '/')
  65                                return NULL;
  66                }
  67        }
  68
  69        return p;
  70}
  71
  72static __be32 *
  73decode_pathname(__be32 *p, char **namp, unsigned int *lenp)
  74{
  75        char            *name;
  76        unsigned int    i;
  77
  78        if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS_MAXPATHLEN)) != NULL) {
  79                for (i = 0, name = *namp; i < *lenp; i++, name++) {
  80                        if (*name == '\0')
  81                                return NULL;
  82                }
  83        }
  84
  85        return p;
  86}
  87
  88static __be32 *
  89decode_sattr(__be32 *p, struct iattr *iap)
  90{
  91        u32     tmp, tmp1;
  92
  93        iap->ia_valid = 0;
  94
  95        /* Sun client bug compatibility check: some sun clients seem to
  96         * put 0xffff in the mode field when they mean 0xffffffff.
  97         * Quoting the 4.4BSD nfs server code: Nah nah nah nah na nah.
  98         */
  99        if ((tmp = ntohl(*p++)) != (u32)-1 && tmp != 0xffff) {
 100                iap->ia_valid |= ATTR_MODE;
 101                iap->ia_mode = tmp;
 102        }
 103        if ((tmp = ntohl(*p++)) != (u32)-1) {
 104                iap->ia_uid = make_kuid(&init_user_ns, tmp);
 105                if (uid_valid(iap->ia_uid))
 106                        iap->ia_valid |= ATTR_UID;
 107        }
 108        if ((tmp = ntohl(*p++)) != (u32)-1) {
 109                iap->ia_gid = make_kgid(&init_user_ns, tmp);
 110                if (gid_valid(iap->ia_gid))
 111                        iap->ia_valid |= ATTR_GID;
 112        }
 113        if ((tmp = ntohl(*p++)) != (u32)-1) {
 114                iap->ia_valid |= ATTR_SIZE;
 115                iap->ia_size = tmp;
 116        }
 117        tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
 118        if (tmp != (u32)-1 && tmp1 != (u32)-1) {
 119                iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
 120                iap->ia_atime.tv_sec = tmp;
 121                iap->ia_atime.tv_nsec = tmp1 * 1000; 
 122        }
 123        tmp  = ntohl(*p++); tmp1 = ntohl(*p++);
 124        if (tmp != (u32)-1 && tmp1 != (u32)-1) {
 125                iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
 126                iap->ia_mtime.tv_sec = tmp;
 127                iap->ia_mtime.tv_nsec = tmp1 * 1000; 
 128                /*
 129                 * Passing the invalid value useconds=1000000 for mtime
 130                 * is a Sun convention for "set both mtime and atime to
 131                 * current server time".  It's needed to make permissions
 132                 * checks for the "touch" program across v2 mounts to
 133                 * Solaris and Irix boxes work correctly. See description of
 134                 * sattr in section 6.1 of "NFS Illustrated" by
 135                 * Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5
 136                 */
 137                if (tmp1 == 1000000)
 138                        iap->ia_valid &= ~(ATTR_ATIME_SET|ATTR_MTIME_SET);
 139        }
 140        return p;
 141}
 142
 143static __be32 *
 144encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
 145             struct kstat *stat)
 146{
 147        struct dentry   *dentry = fhp->fh_dentry;
 148        int type;
 149        struct timespec time;
 150        u32 f;
 151
 152        type = (stat->mode & S_IFMT);
 153
 154        *p++ = htonl(nfs_ftypes[type >> 12]);
 155        *p++ = htonl((u32) stat->mode);
 156        *p++ = htonl((u32) stat->nlink);
 157        *p++ = htonl((u32) from_kuid(&init_user_ns, stat->uid));
 158        *p++ = htonl((u32) from_kgid(&init_user_ns, stat->gid));
 159
 160        if (S_ISLNK(type) && stat->size > NFS_MAXPATHLEN) {
 161                *p++ = htonl(NFS_MAXPATHLEN);
 162        } else {
 163                *p++ = htonl((u32) stat->size);
 164        }
 165        *p++ = htonl((u32) stat->blksize);
 166        if (S_ISCHR(type) || S_ISBLK(type))
 167                *p++ = htonl(new_encode_dev(stat->rdev));
 168        else
 169                *p++ = htonl(0xffffffff);
 170        *p++ = htonl((u32) stat->blocks);
 171        switch (fsid_source(fhp)) {
 172        default:
 173        case FSIDSOURCE_DEV:
 174                *p++ = htonl(new_encode_dev(stat->dev));
 175                break;
 176        case FSIDSOURCE_FSID:
 177                *p++ = htonl((u32) fhp->fh_export->ex_fsid);
 178                break;
 179        case FSIDSOURCE_UUID:
 180                f = ((u32*)fhp->fh_export->ex_uuid)[0];
 181                f ^= ((u32*)fhp->fh_export->ex_uuid)[1];
 182                f ^= ((u32*)fhp->fh_export->ex_uuid)[2];
 183                f ^= ((u32*)fhp->fh_export->ex_uuid)[3];
 184                *p++ = htonl(f);
 185                break;
 186        }
 187        *p++ = htonl((u32) stat->ino);
 188        *p++ = htonl((u32) stat->atime.tv_sec);
 189        *p++ = htonl(stat->atime.tv_nsec ? stat->atime.tv_nsec / 1000 : 0);
 190        lease_get_mtime(dentry->d_inode, &time); 
 191        *p++ = htonl((u32) time.tv_sec);
 192        *p++ = htonl(time.tv_nsec ? time.tv_nsec / 1000 : 0); 
 193        *p++ = htonl((u32) stat->ctime.tv_sec);
 194        *p++ = htonl(stat->ctime.tv_nsec ? stat->ctime.tv_nsec / 1000 : 0);
 195
 196        return p;
 197}
 198
 199/* Helper function for NFSv2 ACL code */
 200__be32 *nfs2svc_encode_fattr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp, struct kstat *stat)
 201{
 202        return encode_fattr(rqstp, p, fhp, stat);
 203}
 204
 205/*
 206 * XDR decode functions
 207 */
 208int
 209nfssvc_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
 210{
 211        return xdr_argsize_check(rqstp, p);
 212}
 213
 214int
 215nfssvc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
 216{
 217        if (!(p = decode_fh(p, &args->fh)))
 218                return 0;
 219        return xdr_argsize_check(rqstp, p);
 220}
 221
 222int
 223nfssvc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
 224                                        struct nfsd_sattrargs *args)
 225{
 226        p = decode_fh(p, &args->fh);
 227        if (!p)
 228                return 0;
 229        p = decode_sattr(p, &args->attrs);
 230
 231        return xdr_argsize_check(rqstp, p);
 232}
 233
 234int
 235nfssvc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
 236                                        struct nfsd_diropargs *args)
 237{
 238        if (!(p = decode_fh(p, &args->fh))
 239         || !(p = decode_filename(p, &args->name, &args->len)))
 240                return 0;
 241
 242         return xdr_argsize_check(rqstp, p);
 243}
 244
 245int
 246nfssvc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
 247                                        struct nfsd_readargs *args)
 248{
 249        unsigned int len;
 250        int v;
 251        if (!(p = decode_fh(p, &args->fh)))
 252                return 0;
 253
 254        args->offset    = ntohl(*p++);
 255        len = args->count     = ntohl(*p++);
 256        p++; /* totalcount - unused */
 257
 258        if (len > NFSSVC_MAXBLKSIZE_V2)
 259                len = NFSSVC_MAXBLKSIZE_V2;
 260
 261        /* set up somewhere to store response.
 262         * We take pages, put them on reslist and include in iovec
 263         */
 264        v=0;
 265        while (len > 0) {
 266                struct page *p = *(rqstp->rq_next_page++);
 267
 268                rqstp->rq_vec[v].iov_base = page_address(p);
 269                rqstp->rq_vec[v].iov_len = len < PAGE_SIZE?len:PAGE_SIZE;
 270                len -= rqstp->rq_vec[v].iov_len;
 271                v++;
 272        }
 273        args->vlen = v;
 274        return xdr_argsize_check(rqstp, p);
 275}
 276
 277int
 278nfssvc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
 279                                        struct nfsd_writeargs *args)
 280{
 281        unsigned int len, hdr, dlen;
 282        int v;
 283
 284        if (!(p = decode_fh(p, &args->fh)))
 285                return 0;
 286
 287        p++;                            /* beginoffset */
 288        args->offset = ntohl(*p++);     /* offset */
 289        p++;                            /* totalcount */
 290        len = args->len = ntohl(*p++);
 291        /*
 292         * The protocol specifies a maximum of 8192 bytes.
 293         */
 294        if (len > NFSSVC_MAXBLKSIZE_V2)
 295                return 0;
 296
 297        /*
 298         * Check to make sure that we got the right number of
 299         * bytes.
 300         */
 301        hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
 302        dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
 303                - hdr;
 304
 305        /*
 306         * Round the length of the data which was specified up to
 307         * the next multiple of XDR units and then compare that
 308         * against the length which was actually received.
 309         * Note that when RPCSEC/GSS (for example) is used, the
 310         * data buffer can be padded so dlen might be larger
 311         * than required.  It must never be smaller.
 312         */
 313        if (dlen < XDR_QUADLEN(len)*4)
 314                return 0;
 315
 316        rqstp->rq_vec[0].iov_base = (void*)p;
 317        rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
 318        v = 0;
 319        while (len > rqstp->rq_vec[v].iov_len) {
 320                len -= rqstp->rq_vec[v].iov_len;
 321                v++;
 322                rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
 323                rqstp->rq_vec[v].iov_len = PAGE_SIZE;
 324        }
 325        rqstp->rq_vec[v].iov_len = len;
 326        args->vlen = v + 1;
 327        return 1;
 328}
 329
 330int
 331nfssvc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
 332                                        struct nfsd_createargs *args)
 333{
 334        if (   !(p = decode_fh(p, &args->fh))
 335            || !(p = decode_filename(p, &args->name, &args->len)))
 336                return 0;
 337        p = decode_sattr(p, &args->attrs);
 338
 339        return xdr_argsize_check(rqstp, p);
 340}
 341
 342int
 343nfssvc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
 344                                        struct nfsd_renameargs *args)
 345{
 346        if (!(p = decode_fh(p, &args->ffh))
 347         || !(p = decode_filename(p, &args->fname, &args->flen))
 348         || !(p = decode_fh(p, &args->tfh))
 349         || !(p = decode_filename(p, &args->tname, &args->tlen)))
 350                return 0;
 351
 352        return xdr_argsize_check(rqstp, p);
 353}
 354
 355int
 356nfssvc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd_readlinkargs *args)
 357{
 358        if (!(p = decode_fh(p, &args->fh)))
 359                return 0;
 360        args->buffer = page_address(*(rqstp->rq_next_page++));
 361
 362        return xdr_argsize_check(rqstp, p);
 363}
 364
 365int
 366nfssvc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
 367                                        struct nfsd_linkargs *args)
 368{
 369        if (!(p = decode_fh(p, &args->ffh))
 370         || !(p = decode_fh(p, &args->tfh))
 371         || !(p = decode_filename(p, &args->tname, &args->tlen)))
 372                return 0;
 373
 374        return xdr_argsize_check(rqstp, p);
 375}
 376
 377int
 378nfssvc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
 379                                        struct nfsd_symlinkargs *args)
 380{
 381        if (   !(p = decode_fh(p, &args->ffh))
 382            || !(p = decode_filename(p, &args->fname, &args->flen))
 383            || !(p = decode_pathname(p, &args->tname, &args->tlen)))
 384                return 0;
 385        p = decode_sattr(p, &args->attrs);
 386
 387        return xdr_argsize_check(rqstp, p);
 388}
 389
 390int
 391nfssvc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
 392                                        struct nfsd_readdirargs *args)
 393{
 394        if (!(p = decode_fh(p, &args->fh)))
 395                return 0;
 396        args->cookie = ntohl(*p++);
 397        args->count  = ntohl(*p++);
 398        if (args->count > PAGE_SIZE)
 399                args->count = PAGE_SIZE;
 400
 401        args->buffer = page_address(*(rqstp->rq_next_page++));
 402
 403        return xdr_argsize_check(rqstp, p);
 404}
 405
 406/*
 407 * XDR encode functions
 408 */
 409int
 410nfssvc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
 411{
 412        return xdr_ressize_check(rqstp, p);
 413}
 414
 415int
 416nfssvc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
 417                                        struct nfsd_attrstat *resp)
 418{
 419        p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 420        return xdr_ressize_check(rqstp, p);
 421}
 422
 423int
 424nfssvc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
 425                                        struct nfsd_diropres *resp)
 426{
 427        p = encode_fh(p, &resp->fh);
 428        p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 429        return xdr_ressize_check(rqstp, p);
 430}
 431
 432int
 433nfssvc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
 434                                        struct nfsd_readlinkres *resp)
 435{
 436        *p++ = htonl(resp->len);
 437        xdr_ressize_check(rqstp, p);
 438        rqstp->rq_res.page_len = resp->len;
 439        if (resp->len & 3) {
 440                /* need to pad the tail */
 441                rqstp->rq_res.tail[0].iov_base = p;
 442                *p = 0;
 443                rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
 444        }
 445        return 1;
 446}
 447
 448int
 449nfssvc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
 450                                        struct nfsd_readres *resp)
 451{
 452        p = encode_fattr(rqstp, p, &resp->fh, &resp->stat);
 453        *p++ = htonl(resp->count);
 454        xdr_ressize_check(rqstp, p);
 455
 456        /* now update rqstp->rq_res to reflect data as well */
 457        rqstp->rq_res.page_len = resp->count;
 458        if (resp->count & 3) {
 459                /* need to pad the tail */
 460                rqstp->rq_res.tail[0].iov_base = p;
 461                *p = 0;
 462                rqstp->rq_res.tail[0].iov_len = 4 - (resp->count&3);
 463        }
 464        return 1;
 465}
 466
 467int
 468nfssvc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
 469                                        struct nfsd_readdirres *resp)
 470{
 471        xdr_ressize_check(rqstp, p);
 472        p = resp->buffer;
 473        *p++ = 0;                       /* no more entries */
 474        *p++ = htonl((resp->common.err == nfserr_eof));
 475        rqstp->rq_res.page_len = (((unsigned long)p-1) & ~PAGE_MASK)+1;
 476
 477        return 1;
 478}
 479
 480int
 481nfssvc_encode_statfsres(struct svc_rqst *rqstp, __be32 *p,
 482                                        struct nfsd_statfsres *resp)
 483{
 484        struct kstatfs  *stat = &resp->stats;
 485
 486        *p++ = htonl(NFSSVC_MAXBLKSIZE_V2);     /* max transfer size */
 487        *p++ = htonl(stat->f_bsize);
 488        *p++ = htonl(stat->f_blocks);
 489        *p++ = htonl(stat->f_bfree);
 490        *p++ = htonl(stat->f_bavail);
 491        return xdr_ressize_check(rqstp, p);
 492}
 493
 494int
 495nfssvc_encode_entry(void *ccdv, const char *name,
 496                    int namlen, loff_t offset, u64 ino, unsigned int d_type)
 497{
 498        struct readdir_cd *ccd = ccdv;
 499        struct nfsd_readdirres *cd = container_of(ccd, struct nfsd_readdirres, common);
 500        __be32  *p = cd->buffer;
 501        int     buflen, slen;
 502
 503        /*
 504        dprintk("nfsd: entry(%.*s off %ld ino %ld)\n",
 505                        namlen, name, offset, ino);
 506         */
 507
 508        if (offset > ~((u32) 0)) {
 509                cd->common.err = nfserr_fbig;
 510                return -EINVAL;
 511        }
 512        if (cd->offset)
 513                *cd->offset = htonl(offset);
 514        if (namlen > NFS2_MAXNAMLEN)
 515                namlen = NFS2_MAXNAMLEN;/* truncate filename */
 516
 517        slen = XDR_QUADLEN(namlen);
 518        if ((buflen = cd->buflen - slen - 4) < 0) {
 519                cd->common.err = nfserr_toosmall;
 520                return -EINVAL;
 521        }
 522        if (ino > ~((u32) 0)) {
 523                cd->common.err = nfserr_fbig;
 524                return -EINVAL;
 525        }
 526        *p++ = xdr_one;                         /* mark entry present */
 527        *p++ = htonl((u32) ino);                /* file id */
 528        p    = xdr_encode_array(p, name, namlen);/* name length & name */
 529        cd->offset = p;                 /* remember pointer */
 530        *p++ = htonl(~0U);              /* offset of next entry */
 531
 532        cd->buflen = buflen;
 533        cd->buffer = p;
 534        cd->common.err = nfs_ok;
 535        return 0;
 536}
 537
 538/*
 539 * XDR release functions
 540 */
 541int
 542nfssvc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
 543                                        struct nfsd_fhandle *resp)
 544{
 545        fh_put(&resp->fh);
 546        return 1;
 547}
 548
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